This is purely from my personal experiences but we have had flights like this with AA and more recently with JB. Sad to say, it happens and I’m personally not willing to put all the blame on the airlines since the chaos in SXM has much to do with the state of flux the airport itself is in.

The good news, however, is if you take the time to write a thorough and concise explanation of what you experienced, the airlines will probably apologize profusely and compensate you generously with miles and/or vouchers for your inconvenience. At least, such was our personal experience with AA. Not so much with JB who gave away our paid for $$ extra space seats after we had checked in and were sitting in the executive lounge awaiting our boarding call.